JP4644217B2 - Foil type hydrodynamic bearing manufacturing equipment - Google Patents

Description

  The present invention relates to an apparatus for manufacturing a foil-type fluid bearing having a stationary holding member that surrounds an outer periphery of a journal via an annular gap, and a foil assembly that is disposed inside the stationary holding member and supports the journal.

  Conventionally, as a bearing of a rotating body that rotates at a high speed of tens of thousands to hundreds of thousands of revolutions / minute, a bearing surface is constituted by a foil, and a fluid is drawn between the shaft and the foil as the shaft rotates, thereby generating fluid pressure. There is known a foil type fluid bearing in which the foil is deformed to form a fluid film in the gap.

  This type of foil-type hydrodynamic bearing has a stationary holding member that surrounds the outer periphery of the journal via an annular gap, and a foil assembly that is disposed inside the stationary holding member and supports the journal. For example, a corrugated bump foil, an annular midfoil, and an annular top foil are sequentially laminated from the radially outer side to the inner side on the inner peripheral surface of the stationary holding member. Each foil member needs to be accurately positioned and attached to the stationary holding member in order to obtain appropriate bearing performance.

  As a technique for attaching the foil member to the stationary holding member, for example, one end of the first and second foil members (top foil and mid foil) is joined to each other to form a rotation preventing fin extending in the radial direction. In addition, there is a foil type fluid bearing in which a flange portion protruding in the radial direction is provided on an elastic support (bump foil), and the rotation prevention fin and the flange portion are mounted in a slot provided in a stationary holding member (for example, a patent) Reference 1).

JP 2005-233427 A

  However, the conventional technique described in Patent Document 1 is intended to prevent rotation of the foil by inserting the anti-rotation fin and the flange portion into the slot, but does not consider the accuracy of positioning of the foil. In addition, since it is necessary to provide a slot in the stationary holding member, there is a problem that it takes time and effort for processing.

  Further, when the foil type fluid bearing has a configuration in which a plurality of bump foils are arranged by welding along the inner peripheral surface of the stationary holding member, it is difficult to apply the above-described conventional technology. . Therefore, the foil type fluid bearing having such a configuration has a disadvantage that a skilled worker is required to accurately position and attach the foil to the stationary holding member.

  The present invention has been devised in view of such problems of the prior art, and a plurality of foils having corrugated portions with respect to the inner peripheral surface of a stationary holding member that surrounds the outer periphery of the journal via an annular gap. It is a main object of the present invention to provide a foil hydrodynamic bearing manufacturing apparatus that can easily position and weld members in the circumferential direction with high accuracy.

  A first invention made to solve the above-described problem is that a plurality of foil members having corrugated portions are arranged in a circumferential direction on an inner peripheral surface of a stationary holding member that surrounds an outer periphery of a journal via an annular gap. A foil type hydrodynamic bearing manufacturing apparatus comprising: a cylindrical outer peripheral portion provided with a corrugated corresponding portion having a shape corresponding to at least a part of the corrugated portion of the foil member, wherein the corrugated corresponding portion is defined as the foil corresponding portion. A positioning member that positions the foil member with respect to the inner peripheral surface of the stationary holding member by being inserted inside the stationary holding member in a state of being engaged with the corrugated portion of the member, The cylindrical outer peripheral portion has a slot that opens along the axial direction, and the foil member is welded to the inner peripheral surface of the stationary holding member from the inside through the slot.

  As 2nd invention made | formed in order to solve the said subject, it is set as the structure provided with the base which supports the said stationary holding member, and the said base has a moving mechanism which moves the said stationary holding member to an axial direction. Can do. In this case, unintentional deformation of the foil member during welding can be effectively prevented by moving the stationary holding member and performing welding in the order from the center of the foil member to both ends.

  As 3rd invention made | formed in order to solve the said subject, It is the structure which has the base which supports the said stationary holding member, and the said base has a rotation mechanism which rotates a stationary holding member around an axial center, can do.

  According to the first aspect of the invention, it becomes possible to position and weld a plurality of foil members having corrugated portions with high accuracy and easily in the circumferential direction with respect to the inner peripheral surface of the stationary holding member. Unintentional deformation of the foil member can be prevented. Further, according to the second invention, since the stationary holding member is moved in the axial direction at the time of welding, the welding axial direction position can be changed without moving the welding electrode. Can be carried out stably with high accuracy. According to the third aspect of the invention, by rotating the stationary holding member during welding, the welding target (any one of the plurality of foil members) or the circumferential direction of welding can be performed without moving the welding electrode. Since the position can be changed, welding can be stably performed with high accuracy.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a side sectional view of a bearing manufactured by a foil type fluid bearing manufacturing apparatus according to the present invention, and FIG. 2 is a perspective view showing a part of the bearing cut away. In each figure, the dimensional ratio in practical use is ignored in order to easily show the relationship between the parts. Also, the welded part of the foil assembly is schematically indicated by ●.

  The foil type hydrodynamic bearing 1 includes a cylindrical static holding member 2 and a foil assembly 3 attached to the inner peripheral surface of the static holding member 2.

  The foil assembly 3 has an annular shape defined between the inner peripheral surface of the stationary holding member 2 and the outer peripheral surface of the journal 4 when the journal 4 whose cross section orthogonal to the axis is substantially circular is inserted. It arrange | positions in the space | gap G of this, and supports the journal 4 rotatably. The foil assembly 3 includes a top foil 5 disposed on the radially inner side, a mid foil 6 disposed on the outer side thereof, and a plurality of bump foils 7 disposed on the outer side thereof. For each of the foils 5 to 7, a material such as a nickel-based alloy having excellent heat resistance and creep resistance is used.

  The top foil 5 is formed by bending a flat sheet material into a substantially cylindrical shape, and welds one end to the upper inner peripheral surface of the stationary holding member 2 and extends the other end in the clockwise direction. It is wound around the journal 4.

  Similar to the top foil 5, the mid foil 6 is obtained by bending a flat sheet material into a substantially cylindrical shape, welding one end thereof to a position adjacent to one end of the top foil 5, and the other end being the top. It extends in the opposite direction to the foil 5 and is superposed over substantially the entire circumference of the outer peripheral surface of the top foil 5.

  The bump foil 7 is a foil member having a corrugated portion for generating the centripetal force of the journal 4. In the present embodiment, the bump foil 7 has a corrugated shape in which a plurality of arch-shaped portions 7 a projecting radially outward are continuous in the circumferential direction, and each end 7 b is welded to the inner peripheral surface of the stationary holding member 2. A plurality of the holding members 2 are arranged in the circumferential direction on the inner peripheral surface of the stationary holding member 2. In each bump foil 7, the top of the arched portion 7 a is in sliding contact with the inner peripheral surface of the stationary holding member 2, and the connecting portion 7 c and the other end 7 d of the arched portions are in sliding contact with the outer peripheral surface of the midfoil 6. The elastic force of the arched portion 7a causes the elastic force in the centripetal direction to always act on the journal 4.

  Next, the structure of the manufacturing apparatus of the foil type fluid bearing according to the present invention will be described.

  FIG. 3 is an exploded perspective view of the foil hydrodynamic bearing manufacturing apparatus according to the present invention, FIG. 4 is a longitudinal sectional view of the manufacturing apparatus, and FIG. 5 is a stationary holding member during welding in the manufacturing apparatus. It is sectional drawing which shows the fixed state of bump foil with respect to.

  As shown in FIGS. 3 and 4, the manufacturing apparatus 11 includes a foil fixing jig (positioning member) 12 for positioning and fixing the bump foil 7 with respect to the stationary holding member 2, and a foil fixing jig 12. A holder member 13 for holding the stationary holding member 2 in which the bump foil 7 in a state fixed to the holder is inserted, a base 14 for supporting the holder member 13, and the bump foil 7 for welding to the stationary holding member 2. A welding device 15 is mainly provided.

  The foil fixing jig 12 has a substantially cylindrical shape, and the bump foil 7 can be fixed between the outer peripheral surface of the foil fixing jig 12 and the inner peripheral surface of the stationary holding member 2 as shown in FIG. The foil fixing jig 12 is provided with a plurality of waveform corresponding portions 21 having a shape corresponding to the waveform of the bump foil 7. Each waveform corresponding portion 21 protrudes from the outer peripheral surface of the foil fixing jig 12, and a cross section perpendicular to the axial direction forms an arch shape corresponding to the arch-shaped portion 7 a of the bump foil 7. A bump on the inner peripheral surface of the stationary holding member 2 is obtained by engaging the corrugated part 21 and the bump foil 7 so that the corrugated part 21 is fitted inside one arched part 7a of the bump foil 7. The foil 7 can be positioned.

  In addition, as long as the waveform corresponding | compatible part 21 functions as a positioning member of the bump foil 7, various changes are possible. In the present embodiment, one waveform corresponding portion 21 is provided for each bump foil 7. However, for example, a configuration in which a plurality of waveform corresponding portions 21 are provided for each bump foil 7 is also possible. Moreover, the shape of the waveform corresponding portion 21 is not limited to the arch shape, and may be any shape as long as it corresponds to at least a part of the waveform of the bump foil 7. For example, the waveform corresponding portion 21 has a concave shape into which the connecting portion 7 c between the arched portions can be fitted. It may be a thing.

  Further, the foil fixing jig 12 has a plurality of slots 22 opened along the substantially axial direction at the outer peripheral portion of the cylinder. The positions of these slots 22 correspond to the positions of the one ends 7 b of the bump foils 7 in the state where the positioning is performed by the waveform corresponding portion 21. The shape of the slot 22 (the length in the axial direction and the length in the circumferential direction) is set so that the welded portion of the end 7 b of the bump foil 7 can be properly exposed inside the foil fixing jig 12. Thereby, it is possible to weld the one end 7 b of the bump foil 7 to the inner peripheral surface of the stationary holding member 2 from the inside of the foil fixing jig 12 through the slot 22. The arrangement and shape of the slot 22 are not limited to those shown here, and various changes can be made as long as the welding site can be appropriately exposed to the inside of the foil fixing jig 12.

  As shown in FIGS. 3 and 4, the holder member 13 includes a cylindrical portion 16 and a flange portion 17 provided at one end thereof, and an opening 18 is provided at the center thereof. As shown in FIG. 4, the opening 18 has an annular recess 18 a that has a diameter that matches the outer diameter of the stationary holding member 2 and that allows the stationary holding member 2 to be fitted therein. An annular recess 18b having a diameter suitable for the outer diameter of the tool 12 and capable of fitting a part of the foil fixing jig 12 is provided.

  As shown in FIGS. 3 and 4, the base 14 includes a base body 31 and a movable support body 32 provided on the base body 31 so as to be movable in a fixed direction. The base 14 has a moving mechanism in which a groove 34 provided on the bottom surface of the movable support 32 is slidably fitted to a linear guide rail 33 provided on the top surface of the base body 31. Thereby, the movable support body 32 can move on the base body 31 along the guide rail 33. A ball plunger 36 is attached to a leg portion 35 provided symmetrically below the movable support 32, and the ball plunger 36 is locked in a plurality of locking holes 37 arranged on the upper surface of the base body 31. As a result, the movable support 32 can be positioned. The support portion 38 of the movable support 32 is provided with an opening 38a having a diameter that matches the outer diameter of the cylindrical portion 16 of the holder member 13, and the cylindrical portion 16 of the holder member 13 has an opening 38a. And the flange portion 17 is supported by the opening portion 38a in a state where the flange portion 17 is in contact with the side surface 38b of the support portion 38.

  Here, the base 14 has a rotating mechanism in which the outer peripheral surface of the cylindrical portion 16 of the holder member 13 is slidably brought into contact with the peripheral surface of the opening 38a, whereby the holder member 13 is movable. The support 32 can be rotated with respect to the support 38. In addition, an index plunger 39 is attached to the upper portion of the support portion 38, and a locking projection 39 a at the tip of the index plunger 39 penetrates to the opening portion 38 a so as to surround the outer peripheral surface of the cylindrical portion 16 of the holder member 13 at regular intervals. It is provided so as to be engageable with the locking holes 41 arranged in the direction. Thereby, it is possible to position the holder member 13 while rotating the holder member 13 by a predetermined pitch in the rotation direction.

  The welding device 15 is a device for spot-welding the bump foil 7 to the inner peripheral surface of the stationary holding member 2 and has a head portion 52 that supports a welding electrode 51 as shown in FIG. is doing. The head portion 52 is disposed in the foil fixing jig 12 during welding, and the bump foil 7 is welded to the inner peripheral surface of the stationary holding member 2 through the slot 22 from the inside. Further, the head portion 52 is supported by an arm (not shown) so as to be movable in the vertical direction (the radial direction of the stationary holding member 2), whereby the tip of the electrode 51 is in contact with the welded portion of the bump foil 7. It is free to connect and disconnect.

  When each bump foil 7 is welded, the head portion 52 is substantially fixed (welded) by the movement of the movable support 32 on the base body 31 and the rotation of the holder member 13 as described above. It is possible to change the welding target (any one of the plurality of bump foils 7) and its welding position by only the vertical movement at the time. With such a configuration, the welding accuracy can be increased.

  Next, a method for manufacturing a foil fluid bearing using the manufacturing apparatus having the above-described configuration will be described.

  First, the operator inserts the waveform corresponding portion 21 of the foil fixing jig 12 into the predetermined arch-shaped portion 7a of each bump foil 7 and inserts them into the stationary holding member 2 in this state, so that the foil fixing treatment is performed. Each bump foil 7 is fixed between the peripheral surface of the tool 12 and the stationary holding member 2. Subsequently, the stationary holding member 2 is fitted into the opening 18 of the holder member 13, and the holder member 13 is inserted and supported in the opening 38 a of the base 14. At this time, as shown in FIG. 5, one end 7 b which is a welding site of one bump foil 7 is exposed to the inside of the foil fixing jig 12 through the slot 22 and can be welded by the electrode 51 of the welding device 15. It becomes.

  For welding the bump foil 7, the head portion 52 of the welding apparatus 15 is lowered from the standby position to the welding execution position (indicated by an imaginary line and a solid line in FIG. 5), and the electrode 51 is brought into contact with the bump foil 7. Do in state. Therefore, when a welding portion having a substantially dot shape is formed at the contact position and welding is completed, the head portion 52 is raised again to the standby position, and as shown by an imaginary line in FIG. The welding position is changed by moving the movable support 32 on the base body 31 by a predetermined amount while remaining stationary. Here, five spot weldings are carried out in the axial direction on one end 7b of one bump foil 7, and this welding is performed in the axial center part A, front end part B, indicated by broken circles in FIG. The welding position is changed in the order of the rear end portion C, the front intermediate portion D, and the rear intermediate portion E. Thereby, distortion of welding can be reduced and the bump foil 7 can be fixed to the stationary holding member 2 with high accuracy.

  When the welding of one end 7b of one bump foil 7 (here, five locations A to E in FIG. 6) is completed, the holder member 13 is rotated and indexed by the index plunger 39. One end 7b of another bump foil 7 to be welded is moved to a position capable of being welded (that is, a position facing the welding electrode 51 shown in FIG. 5). Therefore, welding similar to that described above is performed.

  Such a welding operation is performed on each bump foil 7, and when the welding of all the bump foils 7 is completed, the foil fixing jig 12 is removed, and the mid foil 6 and the top foil 5 are appropriately welded. . Thereby, manufacture of foil type fluid bearing 1 is completed. In addition, about the welding of the mid foil 6 and the top foil 5, it is the same as that of the past, and detailed description is abbreviate | omitted.

  The foil type hydrodynamic bearing manufacturing apparatus according to the present invention provides a plurality of foil members having corrugated portions in the circumferential direction with high accuracy and ease with respect to the inner peripheral surface of the stationary holding member that surrounds the outer periphery of the journal via an annular gap. The foil has a stationary holding member that surrounds the outer periphery of the journal via an annular gap, and a foil assembly that is disposed inside the stationary holding member and supports the journal. This is useful as an apparatus for manufacturing a fluid dynamic bearing.

Side sectional view of a foil type fluid bearing manufactured by the manufacturing apparatus according to the present invention. Perspective view showing a part of a foil type fluid bearing with a part cut away The disassembled perspective view of the manufacturing apparatus which concerns on this invention The longitudinal cross-sectional view of the manufacturing apparatus which concerns on this invention Sectional drawing which shows the fixed state of the bump foil before welding with respect to a stationary holding member Illustration of the bump foil welding sequence

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Foil type fluid bearing 2 Static holding member 3 Foil assembly 4 Journal 7 Bump foil (foil member which makes a waveform)
7a Arched part 11 Manufacturing apparatus 12 Foil fixing jig (positioning member)
13 Holder member 14 Base 15 Welding device 51 Welding electrode 21 Waveform corresponding portion 33 Guide rail 34 Groove

Claims (3)

A foil type hydrodynamic bearing manufacturing apparatus in which a plurality of foil members having corrugated portions are arranged in a circumferential direction with respect to an inner peripheral surface of a stationary holding member surrounding an outer periphery of a journal via an annular gap,
A cylindrical outer peripheral portion provided with a corrugated corresponding portion having a shape corresponding to at least a part of the corrugated portion of the foil member, and the stationary holding in a state where the corrugated corresponding portion is engaged with the corrugated portion of the foil member A positioning member for positioning the foil member with respect to the inner peripheral surface of the stationary holding member by being inserted inside the member;
The positioning member has a slot opened along an axial direction in an outer peripheral portion of the cylinder, and the foil member is welded to the inner peripheral surface of the stationary holding member from the inside through the slot. Foil type hydrodynamic bearing manufacturing equipment.   The apparatus for manufacturing a foil-type fluid bearing according to claim 1, further comprising a base that supports the stationary holding member, and the base includes a moving mechanism that moves the stationary holding member in an axial direction.   2. The foil type fluid bearing according to claim 1, further comprising a base that supports the stationary holding member, wherein the base includes a rotation mechanism that rotates the stationary holding member around an axis. Manufacturing equipment.

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